one million dollar 还是one million dollars .我有一百万your decision can change their lives 还是your decision could change their lives .未发生应该用哪个?原因

one million dollar 还是one million dollars .我有一百万
your decision can change their lives 还是your decision could change their lives .
未发生应该用哪个?原因

dollar 是可数名词,复数要加S,所以 one million dollars 是对的.
可能发生的假设句,用一般现在时来表示.不可能发生的假设句用过去时表示.
这里是可能发生的假设句,所以用 can.
例句：
可能发生的：If I am free this afternoon,I will go to shopping with you.
不可能发生的：If I were you,I would never do it.